Everything about The Heron totally explained
The
herons are wading
birds in the
Ardeidae family. Some are called
egrets or
bitterns instead of herons.
Within the family, all members of the genera
Botaurus and
Ixobrychus are referred to as bitterns, and - including the
Zigzag Heron or Zigzag Bittern - are a
monophyletic group within the Ardeidae. However, egrets are not a biologically distinct group from the herons, and tend to be named differently because they're mainly white and/or have decorative plumes, and while having the same build as the larger herons tend to be smaller.
The classification of the individual heron/egret species is fraught with difficulty, and there's still no clear consensus about the correct placement of many species into either of the two major genera,
Ardea and
Egretta. Similarly, the relationship of the
genera in the family isn't completely resolved. However, one species formerly considered to constitute a separate
monotypic family
Cochlearidae, the
Boat-billed Heron, is now regarded as a member of the Ardeidae.
Although herons resemble birds in some other families, such as the
storks,
ibises and
spoonbills, they differ from these in flying with their necks retracted, not outstretched. They are also one of the bird groups that have
powder down.
The members of this family are mostly associated with
wetlands, and prey on fish, frogs and other aquatic species. Some, like the
Cattle Egret and
Black-headed Heron, also take large insects, and are less tied to watery environments. Some members of this group nest colonially in trees, others, notably the bitterns, use reedbeds.
In February
2005, the
Canadian scientist Dr.
Louis Lefebvre announced a method of measuring avian
IQ in terms of their innovation in feeding habits. Herons were named among the most intelligent birds based on this scale, reflecting a wide variety, flexibility and adaptiveness to acquire food.
Taxonomy and systematics
Analyses of the skeleton, mainly the
skull, suggested that the Ardeidae could be split into a
diurnal and a
crepuscular/
nocturnal group which included the bitterns. From
DNA studies and skeletal analyses focusing more on bones of body and limbs, this grouping has been revealed as incorrect. Rather, the similarities in skull
morphology reflect
convergent evolution to cope with the different challenges of daytime and nighttime feeding. Today, it's believed that three major groups can be distinguished, which are (from the most primitive to the most advanced):
- tiger herons and the boatbill
- bitterns
- day-herons and egrets, and night-herons
The night herons could warrant separation as subfamily
Nycticoracinae, as it was traditionally done. However, the position of some genera (for example
Butorides or
Syrigma) is unclear at the moment, and molecular studies have until now suffered from a small number of studied taxa. Especially the relationship among the ardeine subfamily is very badly resolved. The arrangement presented here should be considered provisional.
Subfamily Tigrisomatinae
Genus Cochlearius - Boat-billed Heron
Genus Tigrisoma - typical tiger-herons (3 species)
Genus Tigriornis - White-crested Tiger-heron
Genus Zonerodius - New Guinea Tiger-heron
Subfamily Botaurinae
Genus Zebrilus - Zigzag Heron
Genus Ixobrychus - small bitterns (8 living species, 1 recently extinct)
Genus Botaurus - large bitterns (4 species)
Subfamily Ardeinae
Genus Zeltornis (fossil)
Genus Nycticorax typical night-herons (2-4 living species, 5 recently extinct; includes Nyctanassa)
Genus Gorsachius - Asian night-herons (3-5 species)
Genus Butorides - green-backed herons (3 species; sometimes included in Ardea)
Genus Agamia - Agami Heron
Genus Pilherodius - Capped Heron
Genus Ardeola pond-herons (6 species)
Genus Bubulcus - cattle-egrets (1-2 species, sometimes included in Ardea)
Genus Proardea (fossil)
Genus Ardea - typical herons (11-17 species)
Genus Syrigma - Whistling Heron
Genus Egretta - typical egrets (7-13 species)
Genus undetermined
- Easter Island Heron, Ardeidae gen. et sp. indet. (prehistoric)
Fossil herons of unresolved affiliations:
Xenerodiops (Early Oligocene of Fayyum, Egypt)
"Anas" basaltica (Late Oligocene of "Warnsdorf", Czechia)
Ardeagradis
Calcardea
Proardeola - possibly same as Proardea
Other prehistoric and fossil species are included in the respective genus accounts.
Further Information
Get more info on 'Heron'.
|
External Link Exchanges
Do you know how hard it is to get a link from a large encyclopaedia? Well we're different and will prove it. To get a link from us just add the following HTML to your site on a relevant page:
<a href="http://heron.totallyexplained.com">Heron Totally Explained</a>
Then simply click through this link from your web page. Our crawlers will verify your link, extract the title of your web page and instantly add a link back to it. If you like you can remove the words Totally Explained and embed the link in article text.
As long as your link remains in place, we'll keep our link to you right here. Please play fair - our crawlers are watching. Your site must be closely related to this one's topic. Any kind of spamming, dubious practises or removing the link will result in your link from us being dropped and, potentially, your whole site being banned. |